A conceptual SAR/altimeter radar with subsurface capabilities, for space missions

A conceptual radar system for planetary explorations is presented. This system´s main features are the recognition of soil composition and surface geometrical characteristics, such as roughness and spatial correlation length, and subsurface sounding. These capabilites are provided to meet the two main requirements in space missions: the safety of the landing phase and the selection of an interesting landing site from a scientific point of view. The proposed system makes use of a real aperture radar for cross-track resolution, a synthetic aperture radar for along-track resolution, and a chirp signal for range resolution. The requirements of a subsurface sounding and the discrimination of subsurface echoes from the surface ones have been met by combining the synthetic aperture and altimeter processing, with a multispectral analysis